1. Field of the Invention
The invention generally relates to a liquid crystal display (LCD) panel, and more particularly, to an LCD panel having a privacy protecting function.
2. Description of Related Art
A display apparatus is required to have the characteristics of wide viewing angles when displaying images, so as to comply with the requirement that a plurality of users can simultaneously watch the images displayed on the same display apparatus. Nevertheless, on certain conditions, such as writing down business information or inputting the personal account number and password into an ATM machine, the characteristics of wide viewing angles of the display apparatus easily lead to the disclosure of users' personal information. Accordingly, the display apparatus is required to have the privacy protecting design, so as to prevent others from spying on the highly confidential data.
At present, a privacy protecting design is proposed and achieved by way of the alignment configuration of a liquid crystal display (LCD) panel. In such privacy protecting technology, the LCD panel in the display apparatus serves to perform the display function. FIG. 1 is a schematic partial view illustrating a conventional LCD panel having the privacy protecting function. With reference to FIG. 1, the display panel 100 is divided into at least one first area I and at least one second area II by dotted lines d1 and d2, for instance. Both the first area I and the second area II include a plurality of first sub-pixels 102 and a plurality of second sub-pixels 104. Each of the first sub-pixels 102 provides a first main alignment vector A1, and each of the second sub-pixels 104 provides a second main alignment vector A2. Here, the alignment vectors A1 and A2 are obtained by quantifying the capacity of the sub-pixels 102 and 104 for aligning liquid crystal and are relevant to the designed alignment direction and the measure of the alignment areas. A direction of the first main alignment vector A1 is opposite to a direction of the second main alignment vector A2.
In order to protect privacy, the LCD panel 100 can enter a narrow viewing angle mode, such that the displayed images can be clearly observed only by the users at the normal viewing angle. Here, the first sub-pixels 102 in the first area I are enabled, the second sub-pixels 104 in the first area I are disabled, the first sub-pixels 102 in the second area II are disabled, and the second sub-pixels 104 in the second area II are enabled. The changes of brightness in the first area I and the second area II of the LCD panel 100 tend to be different when the LCD panel 100 is watched at different polar viewing angles and different azimuth viewing angles. Here, the polar viewing angle refers to the included angle between the observation direction of the user and the baseline when the normal viewing angle direction (defining the 0-degree polar viewing angle) serves as the baseline (i.e., the normal line of the LCD panel), and the azimuth viewing angle refers to the included angle on the horizontal surface between the observation direction of the user and a horizontal axis direction (e.g. the row direction of the pixel array of the LCD panel). By applying said design, the LCD panel 100 can perform the privacy protecting function.
However, as indicated in FIG. 1, only a portion of the first area I or a portion of the second area II in the LCD panel 100 is lighted. From the perspective of users at the normal viewing angle, dark zones DA or bright zones BA can be frequently observed at the junction (e.g., shown by the dotted line d2) of the first and second areas I and II. Hence, the images observed by the user at the normal viewing angle are not clear.